Brian Gilhuly has published a free eBook featuring Eastern Ontario railway history (with maps!). You can view it on the Arnprior and McNab/Braeside Archives site at this link (PDF):
The book features a lot of text and maps discussing the history of railways in Eastern Ontario, from the Bytown and Prescott Railway in 1854 to today's CN / CP / VIA / QGRY lines. The latter part of the book features a series of maps showing the evolution of trackage (and communities) from the beginning of railways in eastern Ontario to today. It's been updated recently to include VIA's acquisition of the CP Brockville subdivision.
Check it out!